The specific aims of the proposed research are to further identify and characterize those host components which are bound to the schistosome tegumental surface and to ascertain the specificity of that binding, to compare the structure of the freshly harvested tegumental membrane with that of a host antigen depleted or cytochemically labeled parasite, to examine the dynamic nature of the tegumental surface with the goal of determining the extent of control the parasite exercises over its surface, and to assess the role of the tegumental cytoskeleton in regulating surface phenomena.